Beverages (e.g., beer, soft drinks, juice drinks, water, dairy products) are sold in a variety of containers such as glass bottles, plastic bottles and containers, aluminum cans, and waxed carton packs. These containers are conveyed through a number of stations in a plant where they are filled with the desired beverage, sealed and labeled. The containers are conveyed from one station to another by a track. The conveyor track is usually made of stainless steel or plastic when the containers are glass bottles, aluminum cans, or a plastic material such as polypropylene or an acetal resin. The conveyor track must be lubricated and cleaned so that the track can continue to move even when the containers on the track are temporarily prevented from advancing such as when a container falls over or gets jammed. If the conveyor track is not properly lubricated, containers may fall over and disrupt the efficient operation of the plant. Critical areas of the conveyor track that typically require lubrication are at the in-feed and discharge points of the rinser, filler, seamer, pasteurizer, and labeler.
Lubricant compositions used for lubricating and cleaning conveyor tracks are generally alkaline based on fatty acids, fatty amines, or phosphate esters. Fatty acid soaps are effective lubricants, but can cause excessive foaming when the conveyor track is moving at high speeds. Moreover, such compositions typically have a high pH (e.g., above about 8). When an acidic beverage (e.g., beer, a soft drink, or orange juice) spills or is rinsed off the container onto the conveyor track, it contacts the fatty acid soap and forms a precipitate on the floor or conveyor track. The precipitated soap is slippery, and can be a source of microbial growth and contamination, particularly when beverage spills occur. Some lubricant compositions are also aggressive to the coloring pigments used to label the surfaces of the containers, particularly steel and aluminum cans used in the beverage industry. The printed matter on the surface of the container may leach into the lubricating composition and fade or distort the printing, making the containers unacceptable for use.
Thus, there is a continuing need for an effective, non-soap based lubricant composition for conveyor tracks that has biocidal properties and does not leach the printed matter on containers transmitted on the conveyor track.